2 * Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
3 * 2000 Wim Taymans <wtay@chello.be>
4 * 2005 Wim Taymans <wim@fluendo.com>
6 * gstobject.c: Fundamental class used for all of GStreamer
8 * This library is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Library General Public
10 * License as published by the Free Software Foundation; either
11 * version 2 of the License, or (at your option) any later version.
13 * This library is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Library General Public License for more details.
18 * You should have received a copy of the GNU Library General Public
19 * License along with this library; if not, write to the
20 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
21 * Boston, MA 02111-1307, USA.
26 * @short_description: Base class for the GStreamer object hierarchy
28 * #GstObject provides a root for the object hierarchy tree filed in by the
29 * GStreamer library. It is currently a thin wrapper on top of
30 * #GObject. It is an abstract class that is not very usable on its own.
32 * #GstObject gives us basic refcounting, parenting functionality and locking.
33 * Most of the function are just extended for special GStreamer needs and can be
34 * found under the same name in the base class of #GstObject which is #GObject
35 * (e.g. g_object_ref() becomes gst_object_ref()).
37 * The most interesting difference between #GstObject and #GObject is the
38 * "floating" reference count. A #GObject is created with a reference count of
39 * 1, owned by the creator of the #GObject. (The owner of a reference is the
40 * code section that has the right to call gst_object_unref() in order to
41 * remove that reference.) A #GstObject is created with a reference count of 1
42 * also, but it isn't owned by anyone; Instead, the initial reference count
43 * of a #GstObject is "floating". The floating reference can be removed by
44 * anyone at any time, by calling gst_object_sink(). gst_object_sink() does
45 * nothing if an object is already sunk (has no floating reference).
47 * When you add a #GstElement to its parent container, the parent container will
51 * gst_object_ref (GST_OBJECT (child_element));
52 * gst_object_sink (GST_OBJECT (child_element));
55 * This means that the container now owns a reference to the child element
56 * (since it called gst_object_ref()), and the child element has no floating
59 * The purpose of the floating reference is to keep the child element alive
60 * until you add it to a parent container, which then manages the lifetime of
64 * element = gst_element_factory_make (factoryname, name);
65 * // element has one floating reference to keep it alive
66 * gst_bin_add (GST_BIN (bin), element);
67 * // element has one non-floating reference owned by the container
71 * Another effect of this is, that calling gst_object_unref() on a bin object,
72 * will also destoy all the #GstElement objects in it. The same is true for
73 * calling gst_bin_remove().
75 * Special care has to be taken for all methods that gst_object_sink() an object
76 * since if the caller of those functions had a floating reference to the object,
77 * the object reference is now invalid.
79 * In contrast to #GObject instances, #GstObject adds a name property. The functions
80 * gst_object_set_name() and gst_object_get_name() are used to set/get the name
84 * <title>controlled properties</title>
86 * Controlled properties offers a lightweight way to adjust gobject
87 * properties over stream-time. It works by using time-stamped value pairs that
88 * are queued for element-properties. At run-time the elements continously pull
89 * values changes for the current stream-time.
91 * What needs to be changed in a #GstElement?
92 * Very little - it is just two steps to make a plugin controllable!
95 * mark gobject-properties paramspecs that make sense to be controlled,
96 * by GST_PARAM_CONTROLLABLE.
99 * when processing data (get, chain, loop function) at the beginning call
100 * gst_object_sync_values(element,timestamp).
101 * This will made the controller to update all gobject properties that are under
102 * control with the current values based on timestamp.
106 * What needs to be done in applications?
107 * Again its not a lot to change.
110 * first put some properties under control, by calling
111 * gst_object_control_properties (object, "prop1", "prop2",...);
114 * create a #GstControlSource.
115 * csource = gst_interpolation_control_source_new ();
116 * g_object_set (csource, "mode", GST_INTERPOLATION_MODE_LINEAR, NULL);
119 * Attach the #GstControlSource on the controller to a property.
120 * gst_object_add_control_binding (object, gst_control_binding_direct_new (objetct, "prop1", csource));
123 * Set the control values
124 * gst_timed_value_control_source_set ((GstTimedValueControlSource *)csource,0 * GST_SECOND, value1);
125 * gst_timed_value_control_source_set ((GstTimedValueControlSource *)csource,1 * GST_SECOND, value2);
128 * start your pipeline
134 * Last reviewed on 2005-11-09 (0.9.4)
137 #include "gst_private.h"
138 #include "glib-compat-private.h"
140 #include "gstobject.h"
141 #include "gstmarshal.h"
142 #include "gstclock.h"
143 #include "gstcontrolbinding.h"
144 #include "gstcontrolsource.h"
146 #include "gstparamspecs.h"
147 #include "gstutils.h"
149 #ifndef GST_DISABLE_TRACE
150 #include "gsttrace.h"
151 static GstAllocTrace *_gst_object_trace;
154 #define DEBUG_REFCOUNT
156 /* Object signals and args */
177 /* maps type name quark => count */
178 static GData *object_name_counts = NULL;
180 G_LOCK_DEFINE_STATIC (object_name_mutex);
182 static void gst_object_set_property (GObject * object, guint prop_id,
183 const GValue * value, GParamSpec * pspec);
184 static void gst_object_get_property (GObject * object, guint prop_id,
185 GValue * value, GParamSpec * pspec);
187 static void gst_object_dispatch_properties_changed (GObject * object,
188 guint n_pspecs, GParamSpec ** pspecs);
190 static void gst_object_dispose (GObject * object);
191 static void gst_object_finalize (GObject * object);
193 static gboolean gst_object_set_name_default (GstObject * object);
195 static guint gst_object_signals[LAST_SIGNAL] = { 0 };
197 static GParamSpec *properties[PROP_LAST];
199 G_DEFINE_ABSTRACT_TYPE (GstObject, gst_object, G_TYPE_INITIALLY_UNOWNED);
202 gst_object_class_init (GstObjectClass * klass)
204 GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
206 #ifndef GST_DISABLE_TRACE
207 _gst_object_trace = gst_alloc_trace_register (g_type_name (GST_TYPE_OBJECT));
210 gobject_class->set_property = gst_object_set_property;
211 gobject_class->get_property = gst_object_get_property;
213 properties[PROP_NAME] =
214 g_param_spec_string ("name", "Name", "The name of the object", NULL,
215 G_PARAM_READWRITE | G_PARAM_CONSTRUCT | G_PARAM_STATIC_STRINGS);
217 properties[PROP_PARENT] =
218 g_param_spec_object ("parent", "Parent", "The parent of the object",
219 GST_TYPE_OBJECT, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS);
221 g_object_class_install_properties (gobject_class, PROP_LAST, properties);
224 * GstObject::deep-notify:
225 * @gstobject: a #GstObject
226 * @prop_object: the object that originated the signal
227 * @prop: the property that changed
229 * The deep notify signal is used to be notified of property changes. It is
230 * typically attached to the toplevel bin to receive notifications from all
231 * the elements contained in that bin.
233 gst_object_signals[DEEP_NOTIFY] =
234 g_signal_new ("deep-notify", G_TYPE_FROM_CLASS (klass),
235 G_SIGNAL_RUN_FIRST | G_SIGNAL_NO_RECURSE | G_SIGNAL_DETAILED |
236 G_SIGNAL_NO_HOOKS, G_STRUCT_OFFSET (GstObjectClass, deep_notify), NULL,
237 NULL, gst_marshal_VOID__OBJECT_PARAM, G_TYPE_NONE, 2, GST_TYPE_OBJECT,
240 klass->path_string_separator = "/";
242 /* see the comments at gst_object_dispatch_properties_changed */
243 gobject_class->dispatch_properties_changed
244 = GST_DEBUG_FUNCPTR (gst_object_dispatch_properties_changed);
246 gobject_class->dispose = gst_object_dispose;
247 gobject_class->finalize = gst_object_finalize;
251 gst_object_init (GstObject * object)
253 g_mutex_init (&object->lock);
254 object->parent = NULL;
256 GST_CAT_TRACE_OBJECT (GST_CAT_REFCOUNTING, object, "%p new", object);
258 #ifndef GST_DISABLE_TRACE
259 gst_alloc_trace_new (_gst_object_trace, object);
264 object->control_rate = 100 * GST_MSECOND;
265 object->last_sync = GST_CLOCK_TIME_NONE;
270 * @object: a #GstObject to reference
272 * Increments the reference count on @object. This function
273 * does not take the lock on @object because it relies on
274 * atomic refcounting.
276 * This object returns the input parameter to ease writing
278 * result = gst_object_ref (object->parent);
280 * Returns: (transfer full): A pointer to @object
283 gst_object_ref (gpointer object)
285 g_return_val_if_fail (object != NULL, NULL);
287 #ifdef DEBUG_REFCOUNT
288 GST_CAT_TRACE_OBJECT (GST_CAT_REFCOUNTING, object, "%p ref %d->%d", object,
289 ((GObject *) object)->ref_count, ((GObject *) object)->ref_count + 1);
291 g_object_ref (object);
298 * @object: a #GstObject to unreference
300 * Decrements the reference count on @object. If reference count hits
301 * zero, destroy @object. This function does not take the lock
302 * on @object as it relies on atomic refcounting.
304 * The unref method should never be called with the LOCK held since
305 * this might deadlock the dispose function.
308 gst_object_unref (gpointer object)
310 g_return_if_fail (object != NULL);
311 g_return_if_fail (((GObject *) object)->ref_count > 0);
313 #ifdef DEBUG_REFCOUNT
314 GST_CAT_TRACE_OBJECT (GST_CAT_REFCOUNTING, object, "%p unref %d->%d", object,
315 ((GObject *) object)->ref_count, ((GObject *) object)->ref_count - 1);
317 g_object_unref (object);
321 * gst_object_ref_sink: (skip)
322 * @object: a #GstObject to sink
324 * Increase the reference count of @object, and possibly remove the floating
325 * reference, if @object has a floating reference.
327 * In other words, if the object is floating, then this call "assumes ownership"
328 * of the floating reference, converting it to a normal reference by clearing
329 * the floating flag while leaving the reference count unchanged. If the object
330 * is not floating, then this call adds a new normal reference increasing the
331 * reference count by one.
334 gst_object_ref_sink (gpointer object)
336 g_return_val_if_fail (object != NULL, NULL);
338 #ifdef DEBUG_REFCOUNT
339 GST_CAT_TRACE_OBJECT (GST_CAT_REFCOUNTING, object, "%p ref_sink %d->%d",
340 object, ((GObject *) object)->ref_count,
341 ((GObject *) object)->ref_count + 1);
343 return g_object_ref_sink (object);
347 * gst_object_replace:
348 * @oldobj: (inout) (transfer full): pointer to a place of a #GstObject to
350 * @newobj: (transfer none): a new #GstObject
352 * Atomically modifies a pointer to point to a new object.
353 * The reference count of @oldobj is decreased and the reference count of
354 * @newobj is increased.
356 * Either @newobj and the value pointed to by @oldobj may be NULL.
358 * Returns: TRUE if @newobj was different from @oldobj
361 gst_object_replace (GstObject ** oldobj, GstObject * newobj)
365 g_return_val_if_fail (oldobj != NULL, FALSE);
367 #ifdef DEBUG_REFCOUNT
368 GST_CAT_TRACE (GST_CAT_REFCOUNTING, "replace %p %s (%d) with %p %s (%d)",
369 *oldobj, *oldobj ? GST_STR_NULL (GST_OBJECT_NAME (*oldobj)) : "(NONE)",
370 *oldobj ? G_OBJECT (*oldobj)->ref_count : 0,
371 newobj, newobj ? GST_STR_NULL (GST_OBJECT_NAME (newobj)) : "(NONE)",
372 newobj ? G_OBJECT (newobj)->ref_count : 0);
375 oldptr = g_atomic_pointer_get ((gpointer *) oldobj);
377 if (G_UNLIKELY (oldptr == newobj))
381 g_object_ref (newobj);
383 while (G_UNLIKELY (!g_atomic_pointer_compare_and_exchange ((gpointer *)
384 oldobj, oldptr, newobj))) {
385 oldptr = g_atomic_pointer_get ((gpointer *) oldobj);
386 if (G_UNLIKELY (oldptr == newobj))
391 g_object_unref (oldptr);
393 return oldptr != newobj;
396 /* dispose is called when the object has to release all links
397 * to other objects */
399 gst_object_dispose (GObject * object)
401 GstObject *self = (GstObject *) object;
404 GST_CAT_TRACE_OBJECT (GST_CAT_REFCOUNTING, object, "dispose");
406 GST_OBJECT_LOCK (object);
407 if ((parent = GST_OBJECT_PARENT (object)))
409 GST_OBJECT_PARENT (object) = NULL;
410 GST_OBJECT_UNLOCK (object);
412 if (self->control_bindings) {
415 for (node = self->control_bindings; node; node = g_list_next (node)) {
416 g_object_unref (node->data);
418 g_list_free (self->control_bindings);
419 self->control_bindings = NULL;
422 ((GObjectClass *) gst_object_parent_class)->dispose (object);
429 g_critical ("\nTrying to dispose object \"%s\", but it still has a "
430 "parent \"%s\".\nYou need to let the parent manage the "
431 "object instead of unreffing the object directly.\n",
432 GST_OBJECT_NAME (object), GST_OBJECT_NAME (parent));
433 GST_OBJECT_UNLOCK (object);
434 /* ref the object again to revive it in this error case */
435 gst_object_ref (object);
440 /* finalize is called when the object has to free its resources */
442 gst_object_finalize (GObject * object)
444 GstObject *gstobject = GST_OBJECT_CAST (object);
446 GST_CAT_TRACE_OBJECT (GST_CAT_REFCOUNTING, object, "finalize");
448 g_signal_handlers_destroy (object);
450 g_free (gstobject->name);
451 g_mutex_clear (&gstobject->lock);
453 #ifndef GST_DISABLE_TRACE
454 gst_alloc_trace_free (_gst_object_trace, object);
457 ((GObjectClass *) gst_object_parent_class)->finalize (object);
460 /* Changing a GObject property of a GstObject will result in "deep-notify"
461 * signals being emitted by the object itself, as well as in each parent
462 * object. This is so that an application can connect a listener to the
463 * top-level bin to catch property-change notifications for all contained
469 gst_object_dispatch_properties_changed (GObject * object,
470 guint n_pspecs, GParamSpec ** pspecs)
472 GstObject *gst_object, *parent, *old_parent;
474 #ifndef GST_DISABLE_GST_DEBUG
476 const gchar *debug_name;
479 /* do the standard dispatching */
481 gst_object_parent_class)->dispatch_properties_changed (object, n_pspecs,
484 gst_object = GST_OBJECT_CAST (object);
485 #ifndef GST_DISABLE_GST_DEBUG
486 if (G_UNLIKELY (_gst_debug_min >= GST_LEVEL_LOG)) {
487 name = gst_object_get_name (gst_object);
488 debug_name = GST_STR_NULL (name);
493 /* now let the parent dispatch those, too */
494 parent = gst_object_get_parent (gst_object);
496 for (i = 0; i < n_pspecs; i++) {
497 GST_CAT_LOG_OBJECT (GST_CAT_PROPERTIES, parent,
498 "deep notification from %s (%s)", debug_name, pspecs[i]->name);
500 g_signal_emit (parent, gst_object_signals[DEEP_NOTIFY],
501 g_quark_from_string (pspecs[i]->name), gst_object, pspecs[i]);
505 parent = gst_object_get_parent (old_parent);
506 gst_object_unref (old_parent);
508 #ifndef GST_DISABLE_GST_DEBUG
514 * gst_object_default_deep_notify:
515 * @object: the #GObject that signalled the notify.
516 * @orig: a #GstObject that initiated the notify.
517 * @pspec: a #GParamSpec of the property.
518 * @excluded_props: (array zero-terminated=1) (element-type gchar*)
519 * (allow-none):a set of user-specified properties to exclude or
520 * NULL to show all changes.
522 * A default deep_notify signal callback for an object. The user data
523 * should contain a pointer to an array of strings that should be excluded
524 * from the notify. The default handler will print the new value of the property
527 * MT safe. This function grabs and releases @object's LOCK for getting its
531 gst_object_default_deep_notify (GObject * object, GstObject * orig,
532 GParamSpec * pspec, gchar ** excluded_props)
534 GValue value = { 0, }; /* the important thing is that value.type = 0 */
538 if (pspec->flags & G_PARAM_READABLE) {
539 /* let's not print these out for excluded properties... */
540 while (excluded_props != NULL && *excluded_props != NULL) {
541 if (strcmp (pspec->name, *excluded_props) == 0)
545 g_value_init (&value, pspec->value_type);
546 g_object_get_property (G_OBJECT (orig), pspec->name, &value);
548 /* FIXME: handle flags */
549 if (G_IS_PARAM_SPEC_ENUM (pspec)) {
550 GEnumValue *enum_value;
551 GEnumClass *klass = G_ENUM_CLASS (g_type_class_ref (pspec->value_type));
553 enum_value = g_enum_get_value (klass, g_value_get_enum (&value));
555 str = g_strdup_printf ("%s (%d)", enum_value->value_nick,
557 g_type_class_unref (klass);
559 str = g_strdup_value_contents (&value);
561 name = gst_object_get_path_string (orig);
562 g_print ("%s: %s = %s\n", name, pspec->name, str);
565 g_value_unset (&value);
567 name = gst_object_get_path_string (orig);
568 g_warning ("Parameter %s not readable in %s.", pspec->name, name);
574 gst_object_set_name_default (GstObject * object)
576 const gchar *type_name;
582 /* to ensure guaranteed uniqueness across threads, only one thread
583 * may ever assign a name */
584 G_LOCK (object_name_mutex);
586 if (!object_name_counts) {
587 g_datalist_init (&object_name_counts);
590 q = g_type_qname (G_OBJECT_TYPE (object));
591 count = GPOINTER_TO_INT (g_datalist_id_get_data (&object_name_counts, q));
592 g_datalist_id_set_data (&object_name_counts, q, GINT_TO_POINTER (count + 1));
594 G_UNLOCK (object_name_mutex);
596 /* GstFooSink -> foosink<N> */
597 type_name = g_quark_to_string (q);
598 if (strncmp (type_name, "Gst", 3) == 0)
600 name = g_strdup_printf ("%s%d", type_name, count);
602 for (i = 0; i < l; i++)
603 name[i] = g_ascii_tolower (name[i]);
605 GST_OBJECT_LOCK (object);
606 if (G_UNLIKELY (object->parent != NULL))
609 g_free (object->name);
612 GST_OBJECT_UNLOCK (object);
619 GST_WARNING ("parented objects can't be renamed");
620 GST_OBJECT_UNLOCK (object);
626 * gst_object_set_name:
627 * @object: a #GstObject
628 * @name: new name of object
630 * Sets the name of @object, or gives @object a guaranteed unique
631 * name (if @name is NULL).
632 * This function makes a copy of the provided name, so the caller
633 * retains ownership of the name it sent.
635 * Returns: TRUE if the name could be set. Since Objects that have
636 * a parent cannot be renamed, this function returns FALSE in those
639 * MT safe. This function grabs and releases @object's LOCK.
642 gst_object_set_name (GstObject * object, const gchar * name)
646 g_return_val_if_fail (GST_IS_OBJECT (object), FALSE);
648 GST_OBJECT_LOCK (object);
650 /* parented objects cannot be renamed */
651 if (G_UNLIKELY (object->parent != NULL))
655 g_free (object->name);
656 object->name = g_strdup (name);
657 GST_OBJECT_UNLOCK (object);
660 GST_OBJECT_UNLOCK (object);
661 result = gst_object_set_name_default (object);
663 /* FIXME-0.11: this misses a g_object_notify (object, "name"); unless called
664 * from gst_object_set_property.
665 * Ideally remove such custom setters (or make it static).
672 GST_WARNING ("parented objects can't be renamed");
673 GST_OBJECT_UNLOCK (object);
679 * gst_object_get_name:
680 * @object: a #GstObject
682 * Returns a copy of the name of @object.
683 * Caller should g_free() the return value after usage.
684 * For a nameless object, this returns NULL, which you can safely g_free()
687 * Free-function: g_free
689 * Returns: (transfer full): the name of @object. g_free() after usage.
691 * MT safe. This function grabs and releases @object's LOCK.
694 gst_object_get_name (GstObject * object)
696 gchar *result = NULL;
698 g_return_val_if_fail (GST_IS_OBJECT (object), NULL);
700 GST_OBJECT_LOCK (object);
701 result = g_strdup (object->name);
702 GST_OBJECT_UNLOCK (object);
708 * gst_object_set_parent:
709 * @object: a #GstObject
710 * @parent: new parent of object
712 * Sets the parent of @object to @parent. The object's reference count will
713 * be incremented, and any floating reference will be removed (see gst_object_ref_sink()).
715 * Returns: TRUE if @parent could be set or FALSE when @object
716 * already had a parent or @object and @parent are the same.
718 * MT safe. Grabs and releases @object's LOCK.
721 gst_object_set_parent (GstObject * object, GstObject * parent)
723 g_return_val_if_fail (GST_IS_OBJECT (object), FALSE);
724 g_return_val_if_fail (GST_IS_OBJECT (parent), FALSE);
725 g_return_val_if_fail (object != parent, FALSE);
727 GST_CAT_DEBUG_OBJECT (GST_CAT_REFCOUNTING, object,
728 "set parent (ref and sink)");
730 GST_OBJECT_LOCK (object);
731 if (G_UNLIKELY (object->parent != NULL))
734 object->parent = parent;
735 gst_object_ref_sink (object);
736 GST_OBJECT_UNLOCK (object);
738 /* FIXME, this does not work, the deep notify takes the lock from the parent
739 * object and deadlocks when the parent holds its lock when calling this
740 * function (like _element_add_pad()) */
741 /* g_object_notify_by_pspec ((GObject *)object, properties[PROP_PARENT]); */
748 GST_CAT_DEBUG_OBJECT (GST_CAT_REFCOUNTING, object,
749 "set parent failed, object already had a parent");
750 GST_OBJECT_UNLOCK (object);
756 * gst_object_get_parent:
757 * @object: a #GstObject
759 * Returns the parent of @object. This function increases the refcount
760 * of the parent object so you should gst_object_unref() it after usage.
762 * Returns: (transfer full): parent of @object, this can be NULL if @object
763 * has no parent. unref after usage.
765 * MT safe. Grabs and releases @object's LOCK.
768 gst_object_get_parent (GstObject * object)
770 GstObject *result = NULL;
772 g_return_val_if_fail (GST_IS_OBJECT (object), NULL);
774 GST_OBJECT_LOCK (object);
775 result = object->parent;
776 if (G_LIKELY (result))
777 gst_object_ref (result);
778 GST_OBJECT_UNLOCK (object);
784 * gst_object_unparent:
785 * @object: a #GstObject to unparent
787 * Clear the parent of @object, removing the associated reference.
788 * This function decreases the refcount of @object.
790 * MT safe. Grabs and releases @object's lock.
793 gst_object_unparent (GstObject * object)
797 g_return_if_fail (GST_IS_OBJECT (object));
799 GST_OBJECT_LOCK (object);
800 parent = object->parent;
802 if (G_LIKELY (parent != NULL)) {
803 GST_CAT_TRACE_OBJECT (GST_CAT_REFCOUNTING, object, "unparent");
804 object->parent = NULL;
805 GST_OBJECT_UNLOCK (object);
807 /* g_object_notify_by_pspec ((GObject *)object, properties[PROP_PARENT]); */
809 gst_object_unref (object);
811 GST_OBJECT_UNLOCK (object);
816 * gst_object_has_ancestor:
817 * @object: a #GstObject to check
818 * @ancestor: a #GstObject to check as ancestor
820 * Check if @object has an ancestor @ancestor somewhere up in
821 * the hierarchy. One can e.g. check if a #GstElement is inside a #GstPipeline.
823 * Returns: TRUE if @ancestor is an ancestor of @object.
825 * MT safe. Grabs and releases @object's locks.
828 gst_object_has_ancestor (GstObject * object, GstObject * ancestor)
830 GstObject *parent, *tmp;
832 if (!ancestor || !object)
835 parent = gst_object_ref (object);
837 if (parent == ancestor) {
838 gst_object_unref (parent);
842 tmp = gst_object_get_parent (parent);
843 gst_object_unref (parent);
851 * gst_object_check_uniqueness:
852 * @list: (transfer none) (element-type Gst.Object): a list of #GstObject to
854 * @name: the name to search for
856 * Checks to see if there is any object named @name in @list. This function
857 * does not do any locking of any kind. You might want to protect the
858 * provided list with the lock of the owner of the list. This function
859 * will lock each #GstObject in the list to compare the name, so be
860 * carefull when passing a list with a locked object.
862 * Returns: TRUE if a #GstObject named @name does not appear in @list,
865 * MT safe. Grabs and releases the LOCK of each object in the list.
868 gst_object_check_uniqueness (GList * list, const gchar * name)
870 gboolean result = TRUE;
872 g_return_val_if_fail (name != NULL, FALSE);
874 for (; list; list = g_list_next (list)) {
878 child = GST_OBJECT_CAST (list->data);
880 GST_OBJECT_LOCK (child);
881 eq = strcmp (GST_OBJECT_NAME (child), name) == 0;
882 GST_OBJECT_UNLOCK (child);
884 if (G_UNLIKELY (eq)) {
894 gst_object_set_property (GObject * object, guint prop_id,
895 const GValue * value, GParamSpec * pspec)
897 GstObject *gstobject;
899 gstobject = GST_OBJECT_CAST (object);
903 gst_object_set_name (gstobject, g_value_get_string (value));
906 gst_object_set_parent (gstobject, g_value_get_object (value));
909 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
915 gst_object_get_property (GObject * object, guint prop_id,
916 GValue * value, GParamSpec * pspec)
918 GstObject *gstobject;
920 gstobject = GST_OBJECT_CAST (object);
924 g_value_take_string (value, gst_object_get_name (gstobject));
927 g_value_take_object (value, gst_object_get_parent (gstobject));
930 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
936 * gst_object_get_path_string:
937 * @object: a #GstObject
939 * Generates a string describing the path of @object in
940 * the object hierarchy. Only useful (or used) for debugging.
942 * Free-function: g_free
944 * Returns: (transfer full): a string describing the path of @object. You must
945 * g_free() the string after usage.
947 * MT safe. Grabs and releases the #GstObject's LOCK for all objects
951 gst_object_get_path_string (GstObject * object)
956 gchar *prevpath, *path;
957 const gchar *typename;
959 const gchar *separator;
961 /* ref object before adding to list */
962 gst_object_ref (object);
963 parentage = g_slist_prepend (NULL, object);
965 path = g_strdup ("");
967 /* first walk the object hierarchy to build a list of the parents,
968 * be carefull here with refcounting. */
970 if (GST_IS_OBJECT (object)) {
971 parent = gst_object_get_parent (object);
972 /* add parents to list, refcount remains increased while
973 * we handle the object */
975 parentage = g_slist_prepend (parentage, parent);
980 } while (object != NULL);
982 /* then walk the parent list and print them out. we need to
983 * decrease the refcounting on each element after we handled
985 for (parents = parentage; parents; parents = g_slist_next (parents)) {
986 if (G_IS_OBJECT (parents->data)) {
987 typename = G_OBJECT_TYPE_NAME (parents->data);
991 if (GST_IS_OBJECT (parents->data)) {
992 GstObject *item = GST_OBJECT_CAST (parents->data);
993 GstObjectClass *oclass = GST_OBJECT_GET_CLASS (item);
994 gchar *objname = gst_object_get_name (item);
996 component = g_strdup_printf ("%s:%s", typename, objname);
997 separator = oclass->path_string_separator;
999 gst_object_unref (item);
1003 component = g_strdup_printf ("%s:%p", typename, parents->data);
1005 component = g_strdup_printf ("%p", parents->data);
1011 path = g_strjoin (separator, prevpath, component, NULL);
1016 g_slist_free (parentage);
1021 /* controller helper functions */
1024 * gst_object_find_control_binding:
1025 * @self: the gobject to search for a property in
1026 * @name: the gobject property name to look for
1028 * Searches the list of properties under control.
1030 * Returns: a #GstControlBinding or %NULL if the property is not being
1033 static GstControlBinding *
1034 gst_object_find_control_binding (GstObject * self, const gchar * name)
1036 GstControlBinding *binding;
1039 for (node = self->control_bindings; node; node = g_list_next (node)) {
1040 binding = node->data;
1041 /* FIXME: eventually use GQuark to speed it up */
1042 if (!strcmp (binding->name, name)) {
1043 GST_DEBUG_OBJECT (self, "found control binding for property '%s'", name);
1047 GST_DEBUG_OBJECT (self, "controller does not manage property '%s'", name);
1052 /* controller functions */
1055 * gst_object_suggest_next_sync:
1056 * @object: the object that has controlled properties
1058 * Returns a suggestion for timestamps where buffers should be split
1059 * to get best controller results.
1061 * Returns: Returns the suggested timestamp or %GST_CLOCK_TIME_NONE
1062 * if no control-rate was set.
1065 gst_object_suggest_next_sync (GstObject * object)
1069 g_return_val_if_fail (GST_IS_OBJECT (object), GST_CLOCK_TIME_NONE);
1070 g_return_val_if_fail (object->control_rate != GST_CLOCK_TIME_NONE,
1071 GST_CLOCK_TIME_NONE);
1073 GST_OBJECT_LOCK (object);
1075 /* TODO: Implement more logic, depending on interpolation mode and control
1077 * FIXME: we need playback direction
1079 ret = object->last_sync + object->control_rate;
1081 GST_OBJECT_UNLOCK (object);
1087 * gst_object_sync_values:
1088 * @object: the object that has controlled properties
1089 * @timestamp: the time that should be processed
1091 * Sets the properties of the object, according to the #GstControlSources that
1092 * (maybe) handle them and for the given timestamp.
1094 * If this function fails, it is most likely the application developers fault.
1095 * Most probably the control sources are not setup correctly.
1097 * Returns: %TRUE if the controller values could be applied to the object
1098 * properties, %FALSE otherwise
1101 gst_object_sync_values (GstObject * object, GstClockTime timestamp)
1104 gboolean ret = TRUE;
1106 g_return_val_if_fail (GST_IS_OBJECT (object), FALSE);
1107 g_return_val_if_fail (GST_CLOCK_TIME_IS_VALID (timestamp), FALSE);
1109 GST_LOG_OBJECT (object, "sync_values");
1110 if (!object->control_bindings)
1113 /* FIXME: this deadlocks */
1114 /* GST_OBJECT_LOCK (object); */
1115 g_object_freeze_notify ((GObject *) object);
1116 for (node = object->control_bindings; node; node = g_list_next (node)) {
1117 ret &= gst_control_binding_sync_values ((GstControlBinding *) node->data,
1118 object, timestamp, object->last_sync);
1120 object->last_sync = timestamp;
1121 g_object_thaw_notify ((GObject *) object);
1122 /* GST_OBJECT_UNLOCK (object); */
1129 * gst_object_has_active_control_bindings:
1130 * @object: the object that has controlled properties
1132 * Check if the @object has an active controlled properties.
1134 * Returns: %TRUE if the object has active controlled properties
1137 gst_object_has_active_control_bindings (GstObject * object)
1139 gboolean res = FALSE;
1142 g_return_val_if_fail (GST_IS_OBJECT (object), FALSE);
1144 GST_OBJECT_LOCK (object);
1145 for (node = object->control_bindings; node; node = g_list_next (node)) {
1146 res |= !gst_control_binding_is_disabled ((GstControlBinding *) node->data);
1148 GST_OBJECT_UNLOCK (object);
1153 * gst_object_set_control_bindings_disabled:
1154 * @object: the object that has controlled properties
1155 * @disabled: boolean that specifies whether to disable the controller
1158 * This function is used to disable all controlled properties of the @object for
1159 * some time, i.e. gst_object_sync_values() will do nothing.
1162 gst_object_set_control_bindings_disabled (GstObject * object, gboolean disabled)
1166 g_return_if_fail (GST_IS_OBJECT (object));
1168 GST_OBJECT_LOCK (object);
1169 for (node = object->control_bindings; node; node = g_list_next (node)) {
1170 gst_control_binding_set_disabled ((GstControlBinding *) node->data,
1173 GST_OBJECT_UNLOCK (object);
1177 * gst_object_set_control_binding_disabled:
1178 * @object: the object that has controlled properties
1179 * @property_name: property to disable
1180 * @disabled: boolean that specifies whether to disable the controller
1183 * This function is used to disable the #GstController on a property for
1184 * some time, i.e. gst_controller_sync_values() will do nothing for the
1188 gst_object_set_control_binding_disabled (GstObject * object,
1189 const gchar * property_name, gboolean disabled)
1191 GstControlBinding *binding;
1193 g_return_if_fail (GST_IS_OBJECT (object));
1194 g_return_if_fail (property_name);
1196 GST_OBJECT_LOCK (object);
1197 if ((binding = gst_object_find_control_binding (object, property_name))) {
1198 gst_control_binding_set_disabled (binding, disabled);
1200 GST_OBJECT_UNLOCK (object);
1205 * gst_object_add_control_binding:
1206 * @object: the controller object
1207 * @binding: (transfer full): the #GstControlBinding that should be used
1209 * Sets the #GstControlBinding. If there already was a #GstControlBinding
1210 * for this property it will be replaced.
1211 * The @object will take ownership of the @binding.
1213 * Returns: %FALSE if the given @binding has not been setup for this object or
1217 gst_object_add_control_binding (GstObject * object, GstControlBinding * binding)
1219 GstControlBinding *old;
1221 g_return_val_if_fail (GST_IS_OBJECT (object), FALSE);
1222 g_return_val_if_fail (GST_IS_CONTROL_BINDING (binding), FALSE);
1223 //g_return_val_if_fail (g_type_is_a (binding->pspec->owner_type,
1224 // G_OBJECT_TYPE (object)), FALSE);
1226 GST_OBJECT_LOCK (object);
1227 if ((old = gst_object_find_control_binding (object, binding->name))) {
1228 GST_DEBUG_OBJECT (object, "controlled property %s removed", old->name);
1229 object->control_bindings = g_list_remove (object->control_bindings, old);
1230 gst_object_unparent (GST_OBJECT_CAST (old));
1232 object->control_bindings = g_list_prepend (object->control_bindings, binding);
1233 gst_object_set_parent (GST_OBJECT_CAST (binding), object);
1234 GST_DEBUG_OBJECT (object, "controlled property %s added", binding->name);
1235 GST_OBJECT_UNLOCK (object);
1241 * gst_object_get_control_binding:
1242 * @object: the object
1243 * @property_name: name of the property
1245 * Gets the corresponding #GstControlBinding for the property. This should be
1246 * unreferenced again after use.
1248 * Returns: (transfer full): the #GstControlBinding for @property_name or %NULL if
1249 * the property is not controlled.
1252 gst_object_get_control_binding (GstObject * object, const gchar * property_name)
1254 GstControlBinding *binding;
1256 g_return_val_if_fail (GST_IS_OBJECT (object), NULL);
1257 g_return_val_if_fail (property_name, NULL);
1259 GST_OBJECT_LOCK (object);
1260 if ((binding = gst_object_find_control_binding (object, property_name))) {
1261 g_object_ref (binding);
1263 GST_OBJECT_UNLOCK (object);
1269 * gst_object_remove_control_binding:
1270 * @object: the object
1271 * @binding: the binding
1273 * Removes the corresponding #GstControlBinding. If it was the
1274 * last ref of the binding, it will be disposed.
1276 * Returns: %TRUE if the binding could be removed.
1279 gst_object_remove_control_binding (GstObject * object,
1280 GstControlBinding * binding)
1283 gboolean ret = FALSE;
1285 g_return_val_if_fail (GST_IS_OBJECT (object), FALSE);
1286 g_return_val_if_fail (GST_IS_CONTROL_BINDING (binding), FALSE);
1288 GST_OBJECT_LOCK (object);
1289 if ((node = g_list_find (object->control_bindings, binding))) {
1290 GST_DEBUG_OBJECT (object, "controlled property %s removed", binding->name);
1291 object->control_bindings =
1292 g_list_delete_link (object->control_bindings, node);
1293 gst_object_unparent (GST_OBJECT_CAST (binding));
1296 GST_OBJECT_UNLOCK (object);
1302 * gst_object_get_value:
1303 * @object: the object that has controlled properties
1304 * @property_name: the name of the property to get
1305 * @timestamp: the time the control-change should be read from
1307 * Gets the value for the given controlled property at the requested time.
1309 * Returns: the GValue of the property at the given time, or %NULL if the
1310 * property isn't controlled.
1313 gst_object_get_value (GstObject * object, const gchar * property_name,
1314 GstClockTime timestamp)
1316 GstControlBinding *binding;
1319 g_return_val_if_fail (GST_IS_OBJECT (object), NULL);
1320 g_return_val_if_fail (property_name, NULL);
1321 g_return_val_if_fail (GST_CLOCK_TIME_IS_VALID (timestamp), NULL);
1323 GST_OBJECT_LOCK (object);
1324 if ((binding = gst_object_find_control_binding (object, property_name))) {
1325 val = gst_control_binding_get_value (binding, timestamp);
1327 GST_OBJECT_UNLOCK (object);
1333 * gst_object_get_value_array:
1334 * @object: the object that has controlled properties
1335 * @property_name: the name of the property to get
1336 * @timestamp: the time that should be processed
1337 * @interval: the time spacing between subsequent values
1338 * @n_values: the number of values
1339 * @values: array to put control-values in
1341 * Gets a number of values for the given controllered property starting at the
1342 * requested time. The array @values need to hold enough space for @n_values of
1343 * the same type as the objects property's type.
1345 * This function is useful if one wants to e.g. draw a graph of the control
1346 * curve or apply a control curve sample by sample.
1348 * Returns: %TRUE if the given array could be filled, %FALSE otherwise
1351 gst_object_get_value_array (GstObject * object, const gchar * property_name,
1352 GstClockTime timestamp, GstClockTime interval, guint n_values,
1355 gboolean res = FALSE;
1356 GstControlBinding *binding;
1358 g_return_val_if_fail (GST_IS_OBJECT (object), FALSE);
1359 g_return_val_if_fail (property_name, FALSE);
1360 g_return_val_if_fail (GST_CLOCK_TIME_IS_VALID (timestamp), FALSE);
1361 g_return_val_if_fail (GST_CLOCK_TIME_IS_VALID (interval), FALSE);
1362 g_return_val_if_fail (values, FALSE);
1364 GST_OBJECT_LOCK (object);
1365 if ((binding = gst_object_find_control_binding (object, property_name))) {
1366 res = gst_control_binding_get_value_array (binding, timestamp, interval,
1369 GST_OBJECT_UNLOCK (object);
1375 * gst_object_get_control_rate:
1376 * @object: the object that has controlled properties
1378 * Obtain the control-rate for this @object. Audio processing #GstElement
1379 * objects will use this rate to sub-divide their processing loop and call
1380 * gst_object_sync_values() inbetween. The length of the processing segment
1381 * should be up to @control-rate nanoseconds.
1383 * If the @object is not under property control, this will return
1384 * %GST_CLOCK_TIME_NONE. This allows the element to avoid the sub-dividing.
1386 * The control-rate is not expected to change if the element is in
1387 * %GST_STATE_PAUSED or %GST_STATE_PLAYING.
1389 * Returns: the control rate in nanoseconds
1392 gst_object_get_control_rate (GstObject * object)
1394 g_return_val_if_fail (GST_IS_OBJECT (object), FALSE);
1396 return object->control_rate;
1400 * gst_object_set_control_rate:
1401 * @object: the object that has controlled properties
1402 * @control_rate: the new control-rate in nanoseconds.
1404 * Change the control-rate for this @object. Audio processing #GstElement
1405 * objects will use this rate to sub-divide their processing loop and call
1406 * gst_object_sync_values() inbetween. The length of the processing segment
1407 * should be up to @control-rate nanoseconds.
1409 * The control-rate should not change if the element is in %GST_STATE_PAUSED or
1410 * %GST_STATE_PLAYING.
1413 gst_object_set_control_rate (GstObject * object, GstClockTime control_rate)
1415 g_return_if_fail (GST_IS_OBJECT (object));
1417 object->control_rate = control_rate;